A Single-Chip 125-MHz to 32-GHz Signal Source in 0.18- $\mu$ m SiGe BiCMOS

We present a 4.4-mm2 single-chip synthesized signal source with 125 MHz to 32 GHz continuous frequency coverage with a minimum frequency step smaller than 10 Hz. The chip is fabricated in a 0.18-μm SiGe BiCMOS 1P6M technology. A core fractional-N synthesizer using a 20-MHz reference frequency has four LC-VCOs and a 4- to 8-GHz synthesizable range. Post-synthesis blocks extend the frequency coverag...